Stretched-exponential scaling, positive

III. Stretched-Exponential Scaling and the Positive Function Renormalization Group (PFRG)... 

Richter et al. carried out neutron spin echo measurements at the minimum position of S(Q) on the same polymer (PB) as that described above [82]. The intermediate scattering functions were described by a stretched exponential function as well, but could not be scaled to a master curve using a shift factor a-j. The relaxation times extracted from the observed stretched exponential functions are plotted in the relaxation time map in Fig. 9, from which it is seen that they deviate from the relaxation time of the a-process and the temperature dependence of Tjg is well described by the Arrhenius formula. It was confirmed that the process observed in PB at the minimum position Q ,j in S(Q) is the JG process. The fact that the JG process is observed at Q jjj suggests that the process is not a cooperative motion but an isolated one. 

---